[Experimental study of renal tubular cells apoptosis subsequent to influenza virus [H9N2] in SPF chickens]

Influenza virus produces cell death in animals and human. Cell death can be caused by either necrosis or apoptosis. We investigated the types of cell death that occur in chickens infected with avian influenza virus [A/chicken/Iran/772/2000[H9N2]. In an experimental study, 60 SPF chickens aged 3 weeks old were assigned to two groups. The first group was infected with 10[7-5] EID50 of the virus intravenously and the second group was treated with saline normal. 72 hours later, renal tissues were collected and fixed in 10% formalin solution. The prepared microscopic sections with the thickness of 5-6 micron were stained using TUNEL method. There was a significant difference in apoptotic cells of renal tubular tissue between the infected group and controls [p<0.005]. We demonstrated that A/chicken/Iran/772/2000 [H9N2] is able to induce apoptosis in renal tubular cells

Pathogenicity and haemagglutinin gene sequence analysis of Iranian avian influenza H9N2 viruses isolated during [1998-2001]

Sixteen avian influenza [AI] H9N2 viruses were isolated from disease outbreaks in different parts of Iran during [1998-2001]. These AI isolates were used for pathogenicity, haemagglutinin [HA] gene variation and phylogenetic analysis. Results in both pathogenicity tests and HA gene cleavage site sequence detection represented a non-highly pathogenic feature for all Iranian AI isolates studied. The cleavage site motif [R-S-S-R] of all AI isolates however, indicated that they had capability of becoming highly pathogenic viruses following 2 nucleotide substitutions at this region. Based on 450 nucleotides region obtained for local isolates and those for referenced viruses available in Gene Bank database used in phylogenetic analysis, all viruses placed on 3 distinct groups, 2 for Iranian and 1 for reference viruses. Among the reference AI viruses, isolates from Pakistan, Saudi Arabia and 1 from Germany showed less differences with Iranian AI isolates. Results also revealed that the circulating viruses in neighbouring provinces have been remained with less mutation for about 2 years

[Experimental study of apoptosis induced by infectious bursal disease virus, using tunel assay]

The purpose of the present in vivo study was to evaluate correlation of the virulence of the infectious bursal disease virus with the rate of apoptotic changes of the immature B lymphocytes in Bursa Fabricius [BF] and lymphoid cells of spleen. Experimental study. 21-day-old SPF chicks of leghorn breed.90 chicks were divided into three groups [TEST-IBDV, TEST -VAC and Control] of30 chicks each. Inoculation of the TEST-IBDV, TEST -VAC and Control groups were done with 1R-499 serotype of high-virulence infectious bursal disease Virus [WIBDV], D78 intermediate vaccine and normal saline, respectively. Furthermore, 20 chicks were categorited into two groups [Test and Control] of 10 chicks each. Test and Control groups were inoculated with WIBDV and normal saline, respectively. 3 days after inoculation, samples of BF and splenic tissues were sent to Pathology Lab for LM, H and Esatinig and TUNEL studies. Kruskal-Wallis, ANOVA and Mann-Whimeytest.LM and H and E staining showed many significant differences among groups. Furthermore, we showed VP2 and VP5, INF-gamma and TNF-alpha were the major inductive factors for development of apoptosis in the immature B lymphocytes of BF and spleen.The present in vivo research showed that there is always a significant correlation between the virulence of the virus and the rate of apoptotic changes in the BF tissue. Moreover, apoptosis can be considered as a definite factor in the pathogenesisof infectious bursaldisease [IBD]